1. Field of the Invention
The invention relates to optical devices used, for example, in communication systems, and, in particular, to interferometers, such as Mach-Zehnder interferometers.
2. Description of the Related Art
As data rates in optical networks increase, electronics-based switching becomes ever more challenging. For instance, detection schemes relying on optical demultiplexing followed by processing at lower data rates may be inevitable at data rates of 160 Gb/s or higher. As opposed to electronic or micro-electro-mechanical systems (MEMS)-based switching or routing, all-optical switching or data processing based on non-linear optical interactions offers the intrinsic double advantage of transparency and ultra-fast processing speeds. The speed in all-optical data processing is limited only by the response time of the relevant optical non-linearity (typically in the 100 s of THz range).
However, the small magnitude of useful non-linearities in most materials implies high switching power levels or long interaction lengths, which constitutes a challenge for the practical implementation of all-optical non-linear devices. Another issue is the fact that useful (refractive) non-linearities are usually accompanied by a deleterious absorptive component.